/*
 * jcmaster.c
 *
 * Copyright (C) 1991-1995, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains master control logic for the JPEG compressor.
 * These routines are concerned with parameter validation, initial setup,
 * and inter-pass control (determining the number of passes and the work
 * to be done in each pass).
 */

#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"


/* Private state */

typedef enum {
    main_pass,      /* input data, also do first output step */
    huff_opt_pass,      /* Huffman code optimization pass */
    output_pass     /* data output pass */
} c_pass_type;

typedef struct {
    struct jpeg_comp_master pub;/* public fields */

    c_pass_type pass_type;  /* the type of the current pass */

    int pass_number;    /* # of passes completed */
    int total_passes;   /* total # of passes needed */

    int scan_number;    /* current index in scan_info[] */
} my_comp_master;

typedef my_comp_master * my_master_ptr;


/*
 * Support routines that do various essential calculations.
 */

LOCAL void
initial_setup( j_compress_ptr cinfo ) {
/* Do computations that are needed before master selection phase */
    int ci;
    jpeg_component_info * compptr;
    long samplesperrow;
    JDIMENSION jd_samplesperrow;

    /* Sanity check on image dimensions */
    if ( ( cinfo->image_height <= 0 ) || ( cinfo->image_width <= 0 )
        || ( cinfo->num_components <= 0 ) || ( cinfo->input_components <= 0 ) ) {
        ERREXIT( cinfo, JERR_EMPTY_IMAGE );
    }

    /* Make sure image isn't bigger than I can handle */
    if ( ( (long) cinfo->image_height > (long) JPEG_MAX_DIMENSION ) ||
        ( (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION ) ) {
        ERREXIT1( cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION );
    }

    /* Width of an input scanline must be representable as JDIMENSION. */
    samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components;
    jd_samplesperrow = (JDIMENSION) samplesperrow;
    if ( (long) jd_samplesperrow != samplesperrow ) {
        ERREXIT( cinfo, JERR_WIDTH_OVERFLOW );
    }

    /* For now, precision must match compiled-in value... */
    if ( cinfo->data_precision != BITS_IN_JSAMPLE ) {
        ERREXIT1( cinfo, JERR_BAD_PRECISION, cinfo->data_precision );
    }

    /* Check that number of components won't exceed internal array sizes */
    if ( cinfo->num_components > MAX_COMPONENTS ) {
        ERREXIT2( cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
                  MAX_COMPONENTS );
    }

    /* Compute maximum sampling factors; check factor validity */
    cinfo->max_h_samp_factor = 1;
    cinfo->max_v_samp_factor = 1;
    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
          ci++, compptr++ ) {
        if ( ( compptr->h_samp_factor <= 0 ) || ( compptr->h_samp_factor > MAX_SAMP_FACTOR ) ||
            ( compptr->v_samp_factor <= 0 ) || ( compptr->v_samp_factor > MAX_SAMP_FACTOR ) ) {
            ERREXIT( cinfo, JERR_BAD_SAMPLING );
        }
        cinfo->max_h_samp_factor = MAX( cinfo->max_h_samp_factor,
                                        compptr->h_samp_factor );
        cinfo->max_v_samp_factor = MAX( cinfo->max_v_samp_factor,
                                        compptr->v_samp_factor );
    }

    /* Compute dimensions of components */
    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
          ci++, compptr++ ) {
        /* Fill in the correct component_index value; don't rely on application */
        compptr->component_index = ci;
        /* For compression, we never do DCT scaling. */
        compptr->DCT_scaled_size = DCTSIZE;
        /* Size in DCT blocks */
        compptr->width_in_blocks = (JDIMENSION)
                                   jdiv_round_up( (long) cinfo->image_width * (long) compptr->h_samp_factor,
                                                 (long) ( cinfo->max_h_samp_factor * DCTSIZE ) );
        compptr->height_in_blocks = (JDIMENSION)
                                    jdiv_round_up( (long) cinfo->image_height * (long) compptr->v_samp_factor,
                                                  (long) ( cinfo->max_v_samp_factor * DCTSIZE ) );
        /* Size in samples */
        compptr->downsampled_width = (JDIMENSION)
                                     jdiv_round_up( (long) cinfo->image_width * (long) compptr->h_samp_factor,
                                                   (long) cinfo->max_h_samp_factor );
        compptr->downsampled_height = (JDIMENSION)
                                      jdiv_round_up( (long) cinfo->image_height * (long) compptr->v_samp_factor,
                                                    (long) cinfo->max_v_samp_factor );
        /* Mark component needed (this flag isn't actually used for compression) */
        compptr->component_needed = TRUE;
    }

    /* Compute number of fully interleaved MCU rows (number of times that
     * main controller will call coefficient controller).
     */
    cinfo->total_iMCU_rows = (JDIMENSION)
                             jdiv_round_up( (long) cinfo->image_height,
                                           (long) ( cinfo->max_v_samp_factor * DCTSIZE ) );
}


#ifdef C_MULTISCAN_FILES_SUPPORTED

LOCAL void
validate_script( j_compress_ptr cinfo ) {
/* Verify that the scan script in cinfo->scan_info[] is valid; also
 * determine whether it uses progressive JPEG, and set cinfo->progressive_mode.
 */
    const jpeg_scan_info * scanptr;
    int scanno, ncomps, ci, coefi, thisi;
    int Ss, Se, Ah, Al;
    boolean component_sent[MAX_COMPONENTS];
#ifdef C_PROGRESSIVE_SUPPORTED
    int * last_bitpos_ptr;
    int last_bitpos[MAX_COMPONENTS][DCTSIZE2];
    /* -1 until that coefficient has been seen; then last Al for it */
#endif

    if ( cinfo->num_scans <= 0 ) {
        ERREXIT1( cinfo, JERR_BAD_SCAN_SCRIPT, 0 );
    }

    /* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1;
     * for progressive JPEG, no scan can have this.
     */
    scanptr = cinfo->scan_info;
    if ( ( scanptr->Ss != 0 ) || ( scanptr->Se != DCTSIZE2 - 1 ) ) {
#ifdef C_PROGRESSIVE_SUPPORTED
        cinfo->progressive_mode = TRUE;
        last_bitpos_ptr = &last_bitpos[0][0];
        for ( ci = 0; ci < cinfo->num_components; ci++ ) {
            for ( coefi = 0; coefi < DCTSIZE2; coefi++ ) {
                *last_bitpos_ptr++ = -1;
            }
        }
#else
        ERREXIT( cinfo, JERR_NOT_COMPILED );
#endif
    } else {
        cinfo->progressive_mode = FALSE;
        for ( ci = 0; ci < cinfo->num_components; ci++ ) {
            component_sent[ci] = FALSE;
        }
    }

    for ( scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++ ) {
        /* Validate component indexes */
        ncomps = scanptr->comps_in_scan;
        if ( ( ncomps <= 0 ) || ( ncomps > MAX_COMPS_IN_SCAN ) ) {
            ERREXIT2( cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN );
        }
        for ( ci = 0; ci < ncomps; ci++ ) {
            thisi = scanptr->component_index[ci];
            if ( ( thisi < 0 ) || ( thisi >= cinfo->num_components ) ) {
                ERREXIT1( cinfo, JERR_BAD_SCAN_SCRIPT, scanno );
            }
            /* Components must appear in SOF order within each scan */
            if ( ( ci > 0 ) && ( thisi <= scanptr->component_index[ci - 1] ) ) {
                ERREXIT1( cinfo, JERR_BAD_SCAN_SCRIPT, scanno );
            }
        }
        /* Validate progression parameters */
        Ss = scanptr->Ss;
        Se = scanptr->Se;
        Ah = scanptr->Ah;
        Al = scanptr->Al;
        if ( cinfo->progressive_mode ) {
#ifdef C_PROGRESSIVE_SUPPORTED
            if ( ( Ss < 0 ) || ( Ss >= DCTSIZE2 ) || ( Se < Ss ) || ( Se >= DCTSIZE2 ) ||
                ( Ah < 0 ) || ( Ah > 13 ) || ( Al < 0 ) || ( Al > 13 ) ) {
                ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
            }
            if ( Ss == 0 ) {
                if ( Se != 0 ) {/* DC and AC together not OK */
                    ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
                }
            } else {
                if ( ncomps != 1 ) {/* AC scans must be for only one component */
                    ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
                }
            }
            for ( ci = 0; ci < ncomps; ci++ ) {
                last_bitpos_ptr = &last_bitpos[scanptr->component_index[ci]][0];
                if ( ( Ss != 0 ) && ( last_bitpos_ptr[0] < 0 ) ) {/* AC without prior DC scan */
                    ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
                }
                for ( coefi = Ss; coefi <= Se; coefi++ ) {
                    if ( last_bitpos_ptr[coefi] < 0 ) {
                        /* first scan of this coefficient */
                        if ( Ah != 0 ) {
                            ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
                        }
                    } else {
                        /* not first scan */
                        if ( ( Ah != last_bitpos_ptr[coefi] ) || ( Al != Ah - 1 ) ) {
                            ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
                        }
                    }
                    last_bitpos_ptr[coefi] = Al;
                }
            }
#endif
        } else {
            /* For sequential JPEG, all progression parameters must be these: */
            if ( ( Ss != 0 ) || ( Se != DCTSIZE2 - 1 ) || ( Ah != 0 ) || ( Al != 0 ) ) {
                ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
            }
            /* Make sure components are not sent twice */
            for ( ci = 0; ci < ncomps; ci++ ) {
                thisi = scanptr->component_index[ci];
                if ( component_sent[thisi] ) {
                    ERREXIT1( cinfo, JERR_BAD_SCAN_SCRIPT, scanno );
                }
                component_sent[thisi] = TRUE;
            }
        }
    }

    /* Now verify that everything got sent. */
    if ( cinfo->progressive_mode ) {
#ifdef C_PROGRESSIVE_SUPPORTED
        /* For progressive mode, we only check that at least some DC data
         * got sent for each component; the spec does not require that all bits
         * of all coefficients be transmitted.  Would it be wiser to enforce
         * transmission of all coefficient bits??
         */
        for ( ci = 0; ci < cinfo->num_components; ci++ ) {
            if ( last_bitpos[ci][0] < 0 ) {
                ERREXIT( cinfo, JERR_MISSING_DATA );
            }
        }
#endif
    } else {
        for ( ci = 0; ci < cinfo->num_components; ci++ ) {
            if ( !component_sent[ci] ) {
                ERREXIT( cinfo, JERR_MISSING_DATA );
            }
        }
    }
}

#endif /* C_MULTISCAN_FILES_SUPPORTED */


LOCAL void
select_scan_parameters( j_compress_ptr cinfo ) {
/* Set up the scan parameters for the current scan */
    int ci;

#ifdef C_MULTISCAN_FILES_SUPPORTED
    if ( cinfo->scan_info != NULL ) {
        /* Prepare for current scan --- the script is already validated */
        my_master_ptr master = (my_master_ptr) cinfo->master;
        const jpeg_scan_info * scanptr = cinfo->scan_info + master->scan_number;

        cinfo->comps_in_scan = scanptr->comps_in_scan;
        for ( ci = 0; ci < scanptr->comps_in_scan; ci++ ) {
            cinfo->cur_comp_info[ci] =
                &cinfo->comp_info[scanptr->component_index[ci]];
        }
        cinfo->Ss = scanptr->Ss;
        cinfo->Se = scanptr->Se;
        cinfo->Ah = scanptr->Ah;
        cinfo->Al = scanptr->Al;
    } else
#endif
    {
        /* Prepare for single sequential-JPEG scan containing all components */
        if ( cinfo->num_components > MAX_COMPS_IN_SCAN ) {
            ERREXIT2( cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
                      MAX_COMPS_IN_SCAN );
        }
        cinfo->comps_in_scan = cinfo->num_components;
        for ( ci = 0; ci < cinfo->num_components; ci++ ) {
            cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci];
        }
        cinfo->Ss = 0;
        cinfo->Se = DCTSIZE2 - 1;
        cinfo->Ah = 0;
        cinfo->Al = 0;
    }
}


LOCAL void
per_scan_setup( j_compress_ptr cinfo ) {
/* Do computations that are needed before processing a JPEG scan */
/* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */
    int ci, mcublks, tmp;
    jpeg_component_info * compptr;

    if ( cinfo->comps_in_scan == 1 ) {

        /* Noninterleaved (single-component) scan */
        compptr = cinfo->cur_comp_info[0];

        /* Overall image size in MCUs */
        cinfo->MCUs_per_row = compptr->width_in_blocks;
        cinfo->MCU_rows_in_scan = compptr->height_in_blocks;

        /* For noninterleaved scan, always one block per MCU */
        compptr->MCU_width = 1;
        compptr->MCU_height = 1;
        compptr->MCU_blocks = 1;
        compptr->MCU_sample_width = DCTSIZE;
        compptr->last_col_width = 1;
        /* For noninterleaved scans, it is convenient to define last_row_height
         * as the number of block rows present in the last iMCU row.
         */
        tmp = (int) ( compptr->height_in_blocks % compptr->v_samp_factor );
        if ( tmp == 0 ) {
            tmp = compptr->v_samp_factor;
        }
        compptr->last_row_height = tmp;

        /* Prepare array describing MCU composition */
        cinfo->blocks_in_MCU = 1;
        cinfo->MCU_membership[0] = 0;

    } else {

        /* Interleaved (multi-component) scan */
        if ( ( cinfo->comps_in_scan <= 0 ) || ( cinfo->comps_in_scan > MAX_COMPS_IN_SCAN ) ) {
            ERREXIT2( cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
                      MAX_COMPS_IN_SCAN );
        }

        /* Overall image size in MCUs */
        cinfo->MCUs_per_row = (JDIMENSION)
                              jdiv_round_up( (long) cinfo->image_width,
                                            (long) ( cinfo->max_h_samp_factor * DCTSIZE ) );
        cinfo->MCU_rows_in_scan = (JDIMENSION)
                                  jdiv_round_up( (long) cinfo->image_height,
                                                (long) ( cinfo->max_v_samp_factor * DCTSIZE ) );

        cinfo->blocks_in_MCU = 0;

        for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
            compptr = cinfo->cur_comp_info[ci];
            /* Sampling factors give # of blocks of component in each MCU */
            compptr->MCU_width = compptr->h_samp_factor;
            compptr->MCU_height = compptr->v_samp_factor;
            compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
            compptr->MCU_sample_width = compptr->MCU_width * DCTSIZE;
            /* Figure number of non-dummy blocks in last MCU column & row */
            tmp = (int) ( compptr->width_in_blocks % compptr->MCU_width );
            if ( tmp == 0 ) {
                tmp = compptr->MCU_width;
            }
            compptr->last_col_width = tmp;
            tmp = (int) ( compptr->height_in_blocks % compptr->MCU_height );
            if ( tmp == 0 ) {
                tmp = compptr->MCU_height;
            }
            compptr->last_row_height = tmp;
            /* Prepare array describing MCU composition */
            mcublks = compptr->MCU_blocks;
            if ( cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU ) {
                ERREXIT( cinfo, JERR_BAD_MCU_SIZE );
            }
            while ( mcublks-- > 0 ) {
                cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
            }
        }

    }

    /* Convert restart specified in rows to actual MCU count. */
    /* Note that count must fit in 16 bits, so we provide limiting. */
    if ( cinfo->restart_in_rows > 0 ) {
        long nominal = (long) cinfo->restart_in_rows * (long) cinfo->MCUs_per_row;
        cinfo->restart_interval = (unsigned int) MIN( nominal, 65535L );
    }
}


/*
 * Per-pass setup.
 * This is called at the beginning of each pass.  We determine which modules
 * will be active during this pass and give them appropriate start_pass calls.
 * We also set is_last_pass to indicate whether any more passes will be
 * required.
 */

METHODDEF void
prepare_for_pass( j_compress_ptr cinfo ) {
    my_master_ptr master = (my_master_ptr) cinfo->master;

    switch ( master->pass_type ) {
        case main_pass:
            /* Initial pass: will collect input data, and do either Huffman
             * optimization or data output for the first scan.
             */
            select_scan_parameters( cinfo );
            per_scan_setup( cinfo );
            if ( !cinfo->raw_data_in ) {
                ( *cinfo->cconvert->start_pass )( cinfo );
                ( *cinfo->downsample->start_pass )( cinfo );
                ( *cinfo->prep->start_pass )( cinfo, JBUF_PASS_THRU );
            }
            ( *cinfo->fdct->start_pass )( cinfo );
            ( *cinfo->entropy->start_pass )( cinfo, cinfo->optimize_coding );
            ( *cinfo->coef->start_pass )( cinfo,
                                         ( master->total_passes > 1 ?
                                           JBUF_SAVE_AND_PASS : JBUF_PASS_THRU ) );
            ( *cinfo->main->start_pass )( cinfo, JBUF_PASS_THRU );
            if ( cinfo->optimize_coding ) {
                /* No immediate data output; postpone writing frame/scan headers */
                master->pub.call_pass_startup = FALSE;
            } else {
                /* Will write frame/scan headers at first jpeg_write_scanlines call */
                master->pub.call_pass_startup = TRUE;
            }
            break;
#ifdef ENTROPY_OPT_SUPPORTED
        case huff_opt_pass:
            /* Do Huffman optimization for a scan after the first one. */
            select_scan_parameters( cinfo );
            per_scan_setup( cinfo );
            if ( ( cinfo->Ss != 0 ) || ( cinfo->Ah == 0 ) || ( cinfo->arith_code ) ) {
                ( *cinfo->entropy->start_pass )( cinfo, TRUE );
                ( *cinfo->coef->start_pass )( cinfo, JBUF_CRANK_DEST );
                master->pub.call_pass_startup = FALSE;
                break;
            }
            /* Special case: Huffman DC refinement scans need no Huffman table
             * and therefore we can skip the optimization pass for them.
             */
            master->pass_type = output_pass;
            master->pass_number++;
            /*FALLTHROUGH*/
#endif
        case output_pass:
            /* Do a data-output pass. */
            /* We need not repeat per-scan setup if prior optimization pass did it. */
            if ( !cinfo->optimize_coding ) {
                select_scan_parameters( cinfo );
                per_scan_setup( cinfo );
            }
            ( *cinfo->entropy->start_pass )( cinfo, FALSE );
            ( *cinfo->coef->start_pass )( cinfo, JBUF_CRANK_DEST );
            /* We emit frame/scan headers now */
            if ( master->scan_number == 0 ) {
                ( *cinfo->marker->write_frame_header )( cinfo );
            }
            ( *cinfo->marker->write_scan_header )( cinfo );
            master->pub.call_pass_startup = FALSE;
            break;
        default:
            ERREXIT( cinfo, JERR_NOT_COMPILED );
    }

    master->pub.is_last_pass = ( master->pass_number == master->total_passes - 1 );

    /* Set up progress monitor's pass info if present */
    if ( cinfo->progress != NULL ) {
        cinfo->progress->completed_passes = master->pass_number;
        cinfo->progress->total_passes = master->total_passes;
    }
}


/*
 * Special start-of-pass hook.
 * This is called by jpeg_write_scanlines if call_pass_startup is TRUE.
 * In single-pass processing, we need this hook because we don't want to
 * write frame/scan headers during jpeg_start_compress; we want to let the
 * application write COM markers etc. between jpeg_start_compress and the
 * jpeg_write_scanlines loop.
 * In multi-pass processing, this routine is not used.
 */

METHODDEF void
pass_startup( j_compress_ptr cinfo ) {
    cinfo->master->call_pass_startup = FALSE;/* reset flag so call only once */

    ( *cinfo->marker->write_frame_header )( cinfo );
    ( *cinfo->marker->write_scan_header )( cinfo );
}


/*
 * Finish up at end of pass.
 */

METHODDEF void
finish_pass_master( j_compress_ptr cinfo ) {
    my_master_ptr master = (my_master_ptr) cinfo->master;

    /* The entropy coder always needs an end-of-pass call,
     * either to analyze statistics or to flush its output buffer.
     */
    ( *cinfo->entropy->finish_pass )( cinfo );

    /* Update state for next pass */
    switch ( master->pass_type ) {
        case main_pass:
            /* next pass is either output of scan 0 (after optimization)
             * or output of scan 1 (if no optimization).
             */
            master->pass_type = output_pass;
            if ( !cinfo->optimize_coding ) {
                master->scan_number++;
            }
            break;
        case huff_opt_pass:
            /* next pass is always output of current scan */
            master->pass_type = output_pass;
            break;
        case output_pass:
            /* next pass is either optimization or output of next scan */
            if ( cinfo->optimize_coding ) {
                master->pass_type = huff_opt_pass;
            }
            master->scan_number++;
            break;
    }

    master->pass_number++;
}


/*
 * Initialize master compression control.
 */

GLOBAL void
jinit_c_master_control( j_compress_ptr cinfo, boolean transcode_only ) {
    my_master_ptr master;

    master = (my_master_ptr)
             ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
                                          SIZEOF( my_comp_master ) );
    cinfo->master = (struct jpeg_comp_master *) master;
    master->pub.prepare_for_pass = prepare_for_pass;
    master->pub.pass_startup = pass_startup;
    master->pub.finish_pass = finish_pass_master;
    master->pub.is_last_pass = FALSE;

    /* Validate parameters, determine derived values */
    initial_setup( cinfo );

    if ( cinfo->scan_info != NULL ) {
#ifdef C_MULTISCAN_FILES_SUPPORTED
        validate_script( cinfo );
#else
        ERREXIT( cinfo, JERR_NOT_COMPILED );
#endif
    } else {
        cinfo->progressive_mode = FALSE;
        cinfo->num_scans = 1;
    }

    if ( cinfo->progressive_mode ) {/*  TEMPORARY HACK ??? */
        cinfo->optimize_coding = TRUE;
    }                              /* assume default tables no good for progressive mode */

    /* Initialize my private state */
    if ( transcode_only ) {
        /* no main pass in transcoding */
        if ( cinfo->optimize_coding ) {
            master->pass_type = huff_opt_pass;
        } else {
            master->pass_type = output_pass;
        }
    } else {
        /* for normal compression, first pass is always this type: */
        master->pass_type = main_pass;
    }
    master->scan_number = 0;
    master->pass_number = 0;
    if ( cinfo->optimize_coding ) {
        master->total_passes = cinfo->num_scans * 2;
    } else {
        master->total_passes = cinfo->num_scans;
    }
}
